Berry U.S. Pat. No. 3,001,925; Pyles U.S. Pat. No. 2,931,764; Berry U.S. Pat. No. 2,782,159; Berkenkotter et al U.S. Pat. No. 2,530,677; Millard U.S. Pat. No. 2,473,290; and Garling et al U.S. Pat. No. 1,880,382 are prior art examples which disclose various different apparatus for electroplating bearing surfaces of a crankshaft when the shaft is submerged in a plating tank containing a plating bath. In these and other known prior art examples of similar apparatus, difficulty has been experienced in conducting current to the crankshaft while concurrently rotating the shaft about the longitudinal axis thereof.
Most crankshafts are massive, and often weigh several hundred pounds. During the electroplating process, the shafts must be rotated for many hours while submerged in a chromic acid electrolyte. A rotatable support means usually supports the shaft and simultaneously provides a means by which current flow to the submerged shaft is achieved. The rotatable support means preferably is provided with a sealed chamber containing mercury so that the mercury simultaneously wets a rotating shaft and housing of the rotatable support means, thereby enabling the housing to become an electrical conductor as well as a main load transferring member by which the weight of the rotating crankshaft is supported within the chromic acid bath. However, the bearings contained within the housing must be lubricated while simultaneously protected from the mercury located on one side thereof as well as the chromic acid solution located on the other side thereof. The chromic acid is incompatible with the bearings; and the mercury, when admixed with the bearing lubricant, is also fatal to the bearing. Accordingly, it is necessary to isolate the mercury from the bearing means and concurrently isolate the bearing means from the chromic acid solution. A current conducting rotating support means which achieves this desirable result is the subject of the present invention.
The current is transferred from the source, through the rotating support means, into the crankshaft, and through the chromic acid solution to an anode. The anode, in accordance with some of the above mentioned prior arts, circumferentially surrounds part of the crankshaft journal to be plated. The anode must be placed in spaced relationship to the journal to be plated, and care must be taken to avoid deposition of chromium on any part of the crankshaft other than the journal to be plated.
Another aspect of the present invention is the provision of improvements in anodes which attain this desirable result, to thereby provide a combination of elements which constitutes the current flow path for the entire plating process.